Trait hecs::serialize::column::SerializeContext

pub trait SerializeContext {
    fn component_count(&self, archetype: &Archetype) -> usize;
    fn serialize_component_ids<S: SerializeTuple>(
        &mut self,
        archetype: &Archetype,
        out: S
    ) -> Result<S::Ok, S::Error>;
    fn serialize_components<S: SerializeTuple>(
        &mut self,
        archetype: &Archetype,
        out: S
    ) -> Result<S::Ok, S::Error>;
}

Available on crate feature column-serialize only.

Implements serialization of archetypes

serialize_component_ids and serialize_components must serialize exactly the number of elements indicated by component_count or return Err.

Data external to the World can be exposed during serialization by storing references inside the struct implementing this trait.

Example

use std::any::TypeId;
use hecs::{*, serialize::column::*};

#[derive(Serialize, Deserialize)]
enum ComponentId { Position, Velocity }

struct Context;

impl SerializeContext for Context {
    fn component_count(&self, archetype: &Archetype) -> usize {
        archetype.component_types()
            .filter(|&t| t == TypeId::of::<Position>() || t == TypeId::of::<Velocity>())
            .count()
    }

    fn serialize_component_ids<S: serde::ser::SerializeTuple>(
        &mut self,
        archetype: &Archetype,
        mut out: S,
    ) -> Result<S::Ok, S::Error> {
        try_serialize_id::<Position, _, _>(archetype, &ComponentId::Position, &mut out)?;
        try_serialize_id::<Velocity, _, _>(archetype, &ComponentId::Velocity, &mut out)?;
        out.end()
    }

    fn serialize_components<S: serde::ser::SerializeTuple>(
        &mut self,
        archetype: &Archetype,
        mut out: S,
    ) -> Result<S::Ok, S::Error> {
        try_serialize::<Position, _>(archetype, &mut out)?;
        try_serialize::<Velocity, _>(archetype, &mut out)?;
        out.end()
    }
}

Required Methods

fn component_count(&self, archetype: &Archetype) -> usize

Number of entries that serialize_component_ids and serialize_components will produce for archetype

fn serialize_component_ids<S: SerializeTuple>(
    &mut self,
    archetype: &Archetype,
    out: S
) -> Result<S::Ok, S::Error>

Serialize the IDs of the components from archetype that will be serialized

fn serialize_components<S: SerializeTuple>(
    &mut self,
    archetype: &Archetype,
    out: S
) -> Result<S::Ok, S::Error>

Serialize component data from archetype into out

For each component ID written by serialize_component_ids, this method must write a tuple containing one value for each entity, e.g. using try_serialize, in the same order. Each tuple’s length must exactly match the number of entities in archetype, and there must be exactly the same number of tuples as there were IDs.

Implementors